3 * Copyright 2015 gRPC authors.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
19 #ifndef GRPC_CORE_LIB_AVL_AVL_H
20 #define GRPC_CORE_LIB_AVL_AVL_H
22 #include <grpc/support/port_platform.h>
24 #include <grpc/support/sync.h>
26 /** internal node of an AVL tree */
27 typedef struct grpc_avl_node {
31 struct grpc_avl_node* left;
32 struct grpc_avl_node* right;
36 /** vtable for the AVL tree
37 * The optional user_data is propagated from the top level grpc_avl_XXX API.
38 * From the same API call, multiple vtable functions may be called multiple
41 typedef struct grpc_avl_vtable {
43 void (*destroy_key)(void* key, void* user_data);
44 /** copy a key, returning new value */
45 void* (*copy_key)(void* key, void* user_data);
46 /** compare key1, key2; return <0 if key1 < key2,
47 >0 if key1 > key2, 0 if key1 == key2 */
48 long (*compare_keys)(void* key1, void* key2, void* user_data);
49 /** destroy a value */
50 void (*destroy_value)(void* value, void* user_data);
52 void* (*copy_value)(void* value, void* user_data);
55 /** "pointer" to an AVL tree - this is a reference
56 counted object - use grpc_avl_ref to add a reference,
57 grpc_avl_unref when done with a reference */
58 typedef struct grpc_avl {
59 const grpc_avl_vtable* vtable;
63 /** Create an immutable AVL tree. */
64 grpc_avl grpc_avl_create(const grpc_avl_vtable* vtable);
65 /** Add a reference to an existing tree - returns
66 the tree as a convenience. The optional user_data will be passed to vtable
68 grpc_avl grpc_avl_ref(grpc_avl avl, void* user_data);
69 /** Remove a reference to a tree - destroying it if there
70 are no references left. The optional user_data will be passed to vtable
72 void grpc_avl_unref(grpc_avl avl, void* user_data);
73 /** Return a new tree with (key, value) added to avl.
74 implicitly unrefs avl to allow easy chaining.
75 if key exists in avl, the new tree's key entry updated
76 (i.e. a duplicate is not created). The optional user_data will be passed to
78 grpc_avl grpc_avl_add(grpc_avl avl, void* key, void* value, void* user_data);
79 /** Return a new tree with key deleted
80 implicitly unrefs avl to allow easy chaining. The optional user_data will be
81 passed to vtable functions. */
82 grpc_avl grpc_avl_remove(grpc_avl avl, void* key, void* user_data);
83 /** Lookup key, and return the associated value.
85 Returns NULL if key is not found. The optional user_data will be passed to
87 void* grpc_avl_get(grpc_avl avl, void* key, void* user_data);
88 /** Return 1 if avl contains key, 0 otherwise; if it has the key, sets *value to
89 its value. The optional user_data will be passed to vtable functions. */
90 int grpc_avl_maybe_get(grpc_avl avl, void* key, void** value, void* user_data);
91 /** Return 1 if avl is empty, 0 otherwise */
92 int grpc_avl_is_empty(grpc_avl avl);
94 #endif /* GRPC_CORE_LIB_AVL_AVL_H */